Image forming apparatus and its control method, and computer program

ABSTRACT

Input print data can assume one of a RGB color space, CMYK color space, and Gray color space. When graphic arts are to be principally printed, data of these color spaces is converted into CIE Color Space XYZ as a standard color space, and data of the standard color space is converted into a CMYK color space according to the Output Profile of a printer, thus printing the converted data. On the other hand, when office documents are to be principally printed, a conversion process into the standard color space is skipped, and input color space data is directly converted into a print color space CMYK, thus printing the converted data.

FIELD OF THE INVENTION

[0001] The present invention relates to a technique for printing inaccordance with data described in a page description language (PDL).

BACKGROUND OF THE INVENTION

[0002] As one of prevalent PDLs, PostScript (which is the registeredtrademark of Adobe Systems Corporation, U.S., and will be abbreviated as“PS” hereinafter) is known. PS Levels 1 and 2 are older versions, and PSLevel 3 is introduced as the current version. With PS Levels 1 and 2,three different color spaces RGB, CMYK, and Gray are selectable, and oneof these color spaces used is obtained by interpreting a description inprint data.

[0003] Therefore, a printer determines which of DeviceRGB, DeviceCMYK,and DeviceGray is used, converts input signals into C (Cyan), M(Magenta), Y (Yellow), and K (Black) on a printer color space by asimple process according to the determination result, and then executesa print process, as shown in FIG. 1. For example, in case of DeviceRGB,i.e., RGB signals (Red, Green, and Blue), an inverse unit (101) inversesthe RGB signals into CMY signals, which undergo an Under Color Removal(UCR) process and Black Generation (BG) process in a UCR & BG unit(102), thus generating CMYK signals. In case of DeviceCMYK, i.e., CMYKsignals, since this color space is the same as the output printer space,the CMYK signals are directly output without any process. Furthermore,in case of DeviceGray, i.e., one Gray color, since the luminance anddensity are inverted, the Gray signal is inverted by an inverse unit(103) to generate a K component, i.e., CMYK signals including only the Kcomponent, thus making a print process.

[0004] On the other hand, PS Level 3 allows to apply a color managementprocess to DeviceRGB, DeviceCMYK, or DeviceGray upon outputting bydesignating a UseCIEColor parameter. That is, if the UseCIEColorparameter is true, a color processing flow shown in FIG. 2 is applied;if it is false, the process shown in FIG. 1 is applied.

[0005] The color management process shown in FIG. 2 will be describedbelow. In case of DeviceRGB, an RGB Source Profile, which is set inadvance, is selected, and DeviceRGB is converted into an XYZ color space(204), which is normalized to specify colors, using the selectedprofile. The XYZ color space is converted into CMYK values in accordancewith an Output Profile (205) as a profile which stores information aboutan appropriate combination of CMYK values to output that XYZ colorspace. In this way, the printer outputs input RGB signals to havecorrect values in terms of chromaticity.

[0006] DeviceCMYK inputs are converted into the XYZ color space (204)using a CMYK Simulation Profile (202), which is set in advance. Also,DeviceGray inputs are converted into the XYZ color space (204) using aGray Profile (203) which is pre-stored in a device. Since the conversionprocess from the converted XYZ color space (204) into CMYK values is thesame as that for DeviceRGB, a description thereof will be omitted.

[0007] Actual flows of respective signals will be explained below usingFIG. 8. When the UseCIEColor parameter=true, DeviceRGB is converted intoCIEBasedABC or CIEBasedDEF, DeviceCMYK is converted into CIEBasedDEFG,and DeviceGray is converted into CIEBasedA. Also, these color spaces areconverted into the XYZ color space as the intermediate color space of PScolor management. Next, the XYZ color space is converted into CMYKvalues according to setups of the Output Profile (205).

[0008] As can be seen from FIG. 8, a larger number of conversionprocesses than in the process shown in FIG. 1 for PS Level 1 or 2 arerequired, and a longer calculation time is required. Especially, in caseof an image with a large bitmap, individual pixels must undergo suchconversion processes, thus taking more time.

[0009] Color management of PS Level 3 shown in FIG. 2 is not switchedfor respective objects which are categorized to Text, Graphics, Image,and the like, and black, e.g., R=G=B=N %, C=Y=M=N %, or K=N % (N=0% to100%), is normally converted into process black as a combination of fourcolors C, M, Y, and K, which represent a chromaticity value optimal to aprinter by color management.

[0010] As described above, the UseCIEColor parameter is normally settrue. Upon outputting even an image, which appears to be a monochromeimage on the screen, to a color printer, it is reproduced using processblack as a combination of four color components C, M, Y, and K by colormanagement, i.e., such image is normally output as a color image.

[0011] Therefore, an image, graphics, and text, which are created orinput by the user as monochrome ones on the screen of a host computer,are output as a color image, graphics, and text. Graphic Arts users whopreferably use PS and place an importance on color tincture in colormanagement rarely feel discontent about the color outputs, and noproblem is posed.

[0012] However, due to spread of PS to offices in recent years, officeusers who create and print documents that mainly include text do notprefer the complicated, time-consuming color management processdescribed above using FIG. 8, since they normally create monochromedocument and require a higher print speed rather than high colorreproducibility. Also, only one UseCIEColor parameter is set for all ofDeviceRGB, DeviceCMYK, and DeviceGray, and cannot be individually set.

[0013] PS Level 3 can define a Separation color space and DeviceN colorspace to cope with an expensive dedicated printing machine which printsusing special color agents, in addition to the above CMYK, RGB, and GRAYcolor spaces. For example, the user of a dedicated printing machine(e.g., an image setter or the like) uses the Separation color space tocope with colors which cannot be reproduced by basic CMYK, and theDeviceN color space to broaden the gamut by adding colors to standardCMYK colors.

[0014] The Separation color space and DeviceN color space are mainlyused in print processes by the dedicated printing machine, whichrequires very high print cost. Therefore, test print processes are oftenmade using a normal color printer using four colors C, M, Y, and K.

[0015] As a problem posed in such case, the Separation color space andDeviceN color space are those for the dedicated printing machine withadvanced functions, and cannot be directly reflected on the color spaceof a normal color printer that uses CMYK color agents. That is, thenormal color printer cannot directly print data of the Separation colorspace and DeviceN color space.

[0016] Hence, PS Level 3 allows a normal color printer to print data ofthe Separation color space and DeviceN color space by describing asubstitute color space.

[0017] For example, the Separation color space is defined as follows. [/Separation  (LogoGreen)  /DeviceCMYK  { dup 0.84 mul  exch 0.0 exch dup0.44 mul  exch 0.21 mul  } ] setcolorspace

[0018] Such description means that print data represents color“LogoGreen”, and its color space corresponds to a space color obtainedby converting parameters described in { . . . } if it is expressed bythe CMYK color space (substitute color space).

[0019] Therefore, when the above print PS data is input, the color spaceof color “LogoGreen” is expressed by parameters of a given CMYK colorspace, and the values of color “LogoGreen” described in print data to besubsequently received are processed to indicate CMYK values on thesubstitute color space.

[0020] A description in case of the DeviceN color space is as follows. [/Indexed  [ /DeviceN   [/Cyan /Black]   /DeviceCMYK   {0 0 3 −1 roll}  ] 255  <6605 6806 6907 6B09 6C0A ...> ] setcolorspace

[0021] This description means that a print process is made using twocolor agents (cyan and black) (an example of N=2 of DeviceN), anddefines conversion into a substitute color space using parametersdefined in subsequent { . . . } when a color space expressed by thesetwo colors is expressed by the substitute color space CMYK.

[0022] As described above, PS Level 3 allows a normal CMYK printer toprint by defining the Separation color space or DeviceN color spaceusing the substitute color space.

[0023] In case of the above example of the Separation color space, sincethe substitute color space CMYK is used, the subsequent process is madeunder the assumption that data on the “CMYK” color space shown in FIG. 2are input. The same applies to the example of the DeviceN color space(when the UseCIEColor parameter=True).

[0024] Upon reception of data of the Separation color space or DeviceNcolor space, many color space conversions, i.e., conversion into thesubstitute color space, conversion of that substitute color space intothe standard color space XYZ, and conversion of the color space XYZ intoCMYK values based on an Output Profile of a printer, are required.Therefore, when an object to be printed is a bitmap image, sinceindividual pixels must undergo these conversion processes, the timerequired for these processes is not negligible, resulting in drop of theprint throughput.

SUMMARY OF THE INVENTION

[0025] It is an object of the present invention to provide a techniquewhich can set even print data described in a page description languagesuch as PostScript Level 3 that realizes high-precision colorreproducibility to print mostly monochrome office documents, and canbuild environments optimal to respective use fields.

[0026] A method of controlling an image forming apparatus according tothe present invention is, for example, a method of controlling an imageforming apparatus, which converts print data into a device-independentstandard color space according to a description of the print data,converts data of the standard color space into a print color spaceaccording to a profile depending on print unit, and prints the converteddata, comprising: a setting step of setting whether or not a conversionprocess into the standard color space is skipped, and storing andholding that setup in predetermined storage means; and a control step ofdirectly converting, when it is set in the setting step that theconversion process into the standard color space is skipped, the printdata into a color space of the print unit according to the descriptionof the print data.

[0027] It is another object of the present invention to provide atechnique which can implement print processes of print data expressed bythe Separation color space or DeviceN color space, which are convenientfor both a user who places an importance on a print speed rather thancolor reproducibility, and a user who wants high-precision colorreproducibility.

[0028] A method of controlling an image forming apparatus according tothe present invention is, for example, a method of controlling an imageforming apparatus which receives print data expressed by a Separationcolor space or DeviceN color space, converts the print data into a printcolor space, and prints the converted data, comprising: a setting stepof setting whether or not color management is applied; a conversion stepof converting the received print data expressed by the Separation colorspace or DeviceN color space into a substitute color space according toa description thereof; a first conversion step of converting, when it isset in the setting step that color management is applied, the colorspace obtained in the conversion step into a print color space via acolor management process; and a second conversion step of converting,when it is set in the setting step that color management is not applied,the color space obtained in the conversion step into a print color spacewithout any color management process.

[0029] Other features and advantages of the present invention will beapparent from the following description taken in conjunction with theaccompanying drawings, in which like reference characters designate thesame or similar parts throughout the figures thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The accompanying drawings, which are incorporated in andconstitute a part of the specification, illustrate embodiments of theinvention and, together with the description, serve to explain theprinciples of the invention.

[0031]FIG. 1 is a diagram for explaining an overview of processes for aconventional print process;

[0032]FIG. 2 is a diagram for explaining an overview of processes for aconventional print process;

[0033]FIG. 3 is a diagram showing an overview of processes for a printprocess according to an embodiment of the present invention;

[0034]FIG. 4 is a flow chart showing a processing sequence uponreception of data of the RGB color space in the embodiment of thepresent invention;

[0035]FIG. 5 is a flow chart showing a processing sequence uponreception of data of the CMYK color space in the embodiment of thepresent invention;

[0036]FIG. 6 is a flow chart showing a processing sequence uponreception of Gray-expressed data in the embodiment of the presentinvention;

[0037]FIG. 7 shows a user interface used to make a switching setup;

[0038]FIG. 8 is a flow chart showing the sequence of a color managementprocess;

[0039]FIG. 9 is a block diagram of a printer in the embodiment of thepresent invention;

[0040]FIG. 10 shows the contents of a nonvolatile memory in theembodiment of the present invention;

[0041]FIG. 11 shows an example of a setting dialog used to set whetheror not color management is applied in the embodiment of the presentinvention;

[0042]FIG. 12 shows the contents of a nonvolatile memory in theembodiment of the present invention; and

[0043]FIG. 13 is a flow chart showing the processing sequence of theprinter the embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0044] Preferred embodiments of the present invention will now bedescribed in detail in accordance with the accompanying drawings.

[0045] <First Embodiment>

[0046]FIG. 9 is a block diagram of a printer to which an embodiment ofthe present invention is applied. Referring to FIG. 9, reference numeral1 denotes a CPU which controls the overall printer; 2, a ROM whichstores the processing sequence of the CPU 1 and font data; and 3, a RAMwhich is used as a work area of the CPU 1. Reference numeral 4 denotes acontrol panel on which a liquid crystal display and various keys arearranged. Reference numeral 5 denotes a nonvolatile memory (for example,a battery backed-up RAM, or an EEPROM, flash memory, or the like), whichholds setup information.

[0047] Reference numeral 6 denotes an interface which receives printdata from a host computer. Note that this printer may serve as a networkprinter. In this case, the interface 6 is connected to a network toreceive print data from a host computer. Reference numeral 7 denotes aframe memory on which bitmap images to be printed (four colors C, M, Y,and K) can be rendered; and 8, a printer engine which actually executesa print process.

[0048] Reference numeral 9 denotes an engine interface which outputsbitmap image data of respective color components rendered on the framememory 7 to the printer engine 8. Note that a laser beam printer enginewill be exemplified as the printer engine. Of course, the presentinvention is not limited to such specific printer engine, and a printerof a type that ejects ink droplets may be used. In this case, the framememory 7 need only have a memory capacity that can store data for one ora plurality of scans of a printhead.

[0049] In the printer of this embodiment with the above arrangement, theuser sets and registers a use purpose and profiles of respective colorspace using the control panel 4. FIG. 7 shows a selection menu displayedon the display of the control panel 4. The user selects, using switches,one of “Office” that prints monochrome office documents at high speedwhen he or she mainly uses this printer to print monochrome officedocuments and does not require high-precision color tincturereproduction, and “Graphic Arts” that executes a print process ofGraphic Arts and the like with high color reproducibility. When the userselects “Graphic Arts”, he or she also selects profiles of color spacesRGB, CMYK, and Gray designated by print data.

[0050] For example, when print data described in the color space RGB isreceived, the user can select a profile to be used from:

[0051] sRGB

[0052] HDTV γ1.5

[0053] HDTV γ1.8

[0054] HDTV γ2.4

[0055] Custom

[0056] None

[0057] sRGB, HDTV γ1.5, HDTV γ1.8, and HDTV γ2.4 are profiles used uponconverting the color space RGB into a standard color space XYZ, and havedifferent conversion levels. Custom is prepared when the user wants tocreate or download his or her favorite profile (upon reception of apredetermined command from a host computer, a subsequent profile isstored and held). None means that no profile is used.

[0058] In case of CMYK, the user selects a profile from SWOP, EuroScale,JapanColor, Custom, and None. In case of Gray, the user sets a flagindicating whether or not a conversion process into the XYZ color spaceusing a profile is to be inserted (if the flag is OFF, it is equivalentto None).

[0059] As described above, when the user selects “Graphic Arts”, he orshe can designate a profile to be used for each type of print data to bereceived.

[0060] On the other hand, when the user selects “Office” on the displaymenu in FIG. 7, the need for an individual setting process of the colorspace RGB, CMYK, or GRAY designated by print data can be obviated, andNone is set.

[0061] After the above setting/registration process, the nonvolatilememory 5 stores and holds the setting contents according to the colorspaces of print data, as shown in FIG. 10. Since the nonvolatile memory5 can hold its storage contents, a print process is done according tothe previous setting contents even when the power switch of the printeris turned on again.

[0062] The operation processes in this embodiment will be describedbelow.

[0063] A sequence upon reception of DeviceRGB data will be explainedbelow with reference to FIG. 4.

[0064] Upon reception of DeviceRGB print data, “RGB Source Profile” inthe nonvolatile memory 4 is loaded in step S1. The flow advances to stepS2 to determine whether or not the loaded contents are “None”. If it isdetermined that the loaded contents are “None”, the flow advances tostep S3 to execute a print process by converting input RGB data intoCMYK data without any color management process. As shown in FIG. 3,luminance RGB data undergo an inversion process (also called LOGconversion) by an inverse unit 101 to generate density CMY data, whichthen undergo UCR and BG processes so as to render CMYK color componentdata. After that, these data are printed.

[0065] If it is determined in step S2 that the contents are other than“None”, the flow advances to step S4 to execute a print process byconverting received RGB data into the standard color space XYZ inaccordance with a profile registered in the loaded “RGB Source Profile”,and converting data on the XYZ color space to a device-dependent CMYKcolor space. As shown in FIG. 3, luminance RGB data are converted intothe standard color space XYZ by a CIE Color Space XYZ converter 204, anddata on the XYZ color space are converted into a CMYK color space inaccordance with an Output Profile depending on a device, i.e., theprinter engine by a CMYK converter 205 to generate CMYK color componentdata. After that, the generated data are printed.

[0066] A process executed upon reception of print data expressed byDeviceCMYK will be explained below with reference to FIG. 3 and the flowchart of FIG. 5.

[0067] In step S11, “CMYK Simulation Profile” in the nonvolatile memory5 is loaded. It is checked in step S12 if the contents of the loaded“CMYK Simulation Profile” are “None”.

[0068] If it is determined that the contents are “None”, the flowadvances to step S13 to execute a print process using input CMYK datawithout any color management process. As shown in FIG. 3, as an exampleof this route, CMYK bitmap data are directly generated based on receivedCMYK data without the intervention of a CIE Color Space XYZ converter,and are printed.

[0069] If it is determined in step S12 that the contents are other than“None”, the flow advances to step S14 to execute a print process byconverting received CMYK data into the standard color space XYZ inaccordance with a profile registered in the loaded “CMYK SimulationProfile”, and then converting the data on the XYZ color space into adevice-dependent CMYK color space. As shown in FIG. 3, this processcorresponds to a route for converting density data CMYK into thestandard color space XYZ by the CIE color Space XYZ converter 204, andthen converting data on the color space XYZ into a CMYK color space inaccordance with an Output Profile which depends on a device, i.e., theprinter engine, by the CMYK converter 205.

[0070] A process executed upon reception of print data expressed by aDeviceGray signal will be described below with reference to FIG. 3 andthe flow chart of FIG. 6.

[0071] In step S21, “Gray Profile” in the nonvolatile memory 5 isloaded. It is determined in step S22 based on the loaded “Gray Profile”if its flag is Off, i.e., if a profile is to be used.

[0072] If it is determined that no gray profile is used, the flowadvances to step S23 to generate density data by simply inverting inputluminance component data, thus executing a print process. As shown inFIG. 3, as an example of this route, received Gray data (luminance data)is directly converted into density data by an inverse unit 103 withoutthe intervention of a CIE Color Space XYZ converter. Note that a colorcomponent used upon printing is only a K component, and other CMYcomponents are not used. As a result, since no chromatic colorcomponents are used, a gray print process is literally implemented.

[0073] If it is determined in step S22 that the flag is ON, i.e., a Grayprofile is used, the flow advances to step S24 to execute a printprocess by converting received gray data into the standard color spaceXYZ in accordance with a Gray Profile which is registered in advance,and then converting data on the XYZ color space into a device-dependentCMYK color space. As shown in FIG. 3, this process corresponds to aroute for converting Gray data into the standard color space XYZ by theCIE Color Space XYZ converter 204, and converting data on the XYZ colorspace into a CMYK color space in accordance with an Output profile whichdepends on a device, i.e., the printer engine by the CMYK converter 205.

[0074] As described above, according to this embodiment, PS Level 3,i.e., an advanced page description language which is particularlyeffective for specialized fields such as graphics arts and the like andcan realize high color reproducibility, can be set to print officedocuments such as general monochrome documents and documents thatinclude some bar graphs, illustrations, and the like, and do not requireany artistry. Especially, most of office documents are monochrome.Hence, as long as “Office” is selected (or “None” is selected for eachindividual color space) as in this embodiment, monochrome documents canbe avoided from being printed as color documents, thus reducing runningcost. In case of a color laser beam printer, scan exposure processescorresponding in number to color components are required. In case of anink-jet printer, the number of nozzles of a monochrome printhead islarger than those of color heads. Therefore, when “Office” is set, ahigh print process speed can be assured only for a GrayScale printprocess. According to this embodiment, when “Office” is selected as ause purpose, “None” can be set for all three different color spacesdesignated by print data, and a user who almost exclusively createsoffice documents can complete a setup process by a simple operation.

[0075] This embodiment has exemplified a case wherein the printerreceives PS Level 3 print data (one of the RGB, CMYK, and Gray colorspaces), and processes the print data according to the setup contents ofuser's choice.

[0076] However, a host computer may execute processes until CMYK data tobe finally output are generated. In this case, the setup contents ofuser's choice (corresponding to FIG. 10) may be saved in a hard disk orthe like of the host computer, and the above processes may beimplemented by a printer driver or an add-on program of a PS printerdriver. That is, the scope of the present invention includes a computerprogram. Since a program which runs on a host computer becomes normallyready to run after a computer readable storage medium such as a CD-ROMor the like is set and the program is copied or installed in a system,such computer readable storage medium is also included in the scope ofthe present invention.

[0077] This embodiment has exemplified PS Level 3. However, the presentinvention is not limited to PS Level 3 since it can be applied to anyother printer description languages which convert into adevice-independent standard color space to realize high colorreproducibility.

[0078] As described above, in this embodiment, in order to allow bothoffice users and Graphic Arts users to select their preferred processes,means which allows the user to independently set from the consolewhether or not a color management process is applied to each ofDeviceRGB, DeviceCMYK, and DeviceGray, is provided, as shown in FIG. 7,thus making setups according to the user's preference.

[0079] In a personal computer, since a display device adopts an RGBcolor space, the RGB color space is often used unless the user selectsanother color space on purpose. Hence, color management=“OFF” is set asdefaults of DeviceCMYK and DeviceGray, since such color spaces are usedonly when the user selects them on purpose. In this manner, only a Kcomponent signal of DeviceCMYK and a DeviceGray Signal, which appears toblack on the screen, is output using one color K, which is also outputby the printer. Since the time-consuming color management process inFIG. 8 can be skipped, the processing speed can be greatly increased.

[0080] As for RGB, color management is indispensable to adjust the colortinctures of the monitor and output. Hence, color management=“ON” is setas a default, i.e., a profile used in color management is selected inadvance. In this manner, the color tinctures of the monitor andprintouts can be adjusted.

[0081] As described above, according to the embodiment of the presentinvention, even data of a page description language for graphic arts,which realizes advanced color reproduction, can be set to print mostlymonochrome office documents, and an optimal environment to each usefield can be provided.

[0082] According to the embodiment of the present invention, in order toallow both office users and Graphic Arts users to select their preferredprocesses, means which allows the user to independently set from theconsole whether or not a color management process is applied to each ofDeviceRGB, DeviceCMYK, and DeviceGray, is provided, thus making setupsaccording to the user's preference.

[0083] In a personal computer, since a display device adopts an RGBcolor space, the RGB color space is often used unless the user selectsanother color space on purpose. Hence, color management=“OFF” is set asdefaults of DeviceCMYK and DeviceGray, since such color spaces are usedonly when the user selects them on purpose. In this manner, only a Kcomponent signal of DeviceCMYK and a DeviceGray Signal, which appears toblack on the screen, is output using one color K, which is also outputby the printer. Since the time-consuming color management process inFIG. 8 can be skipped, the processing speed can be greatly increased.

[0084] As for RGB, color management is indispensable to adjust the colortinctures of the monitor and output. Hence, color management=“ON” is setas a default, i.e., a profile used in color management is selected inadvance. In this manner, the color tinctures of the monitor andprintouts can be adjusted.

[0085] <Second Embodiment>

[0086] In the printer according to this embodiment with the arrangementshown in FIG. 9, the user sets and registers a use purpose using thecontrol panel 4. FIG. 11 shows a selection menu displayed on the displayof the control panel 4. This menu allows the user to set whether or notcolor management is applied upon reception of print data of theSeparation color space or DeviceN color space. This setup is made bytouching a corresponding button if the control panel 4 comprises a touchpanel. Alternatively, physical switches may be used to select.

[0087] In this case, when the user selects “ON”, and data of theSeparation or DeviceN color space is received, that data is convertedinto a substitute color space. After this conversion, processesincluding the color management process, i.e., conversion into thestandard color space XYZ using a color profile (designated by the user)and conversion into a CMYK color space using an Output Profile, areexecuted, and a print process is then executed, according to theprocedure shown in FIG. 2.

[0088] On the other hand, when the user selects “OFF” and data of theSeparation or DeviceN color space is received, a process for convertingthat data into a substitute color space is executed. However, insubsequent processes, conversion into the standard color space XYZ isskipped, and conversion into the CMYK color space is simply done toexecute a print process, as shown in FIG. 1. If the substitute colorspace is CMYK, the subsequent conversion process can also be skipped,and a print process is directly executed.

[0089] Therefore, when the user selects “OFF”, although slightlyunintended color tinctures may be produced compared to a case whereinthe user selects “ON”, since the number of color conversion processescan be reduced (only once when the substitute color space=CMYK), ahigh-speed print process can be assured, and a state optimal to officedocuments can be provided.

[0090] After the aforementioned setup process on the control panel 4,the nonvolatile memory 5 stores and holds setups (ON/OFF flags)indicating whether or not a color management process is applied to eachof the Separation color space and DeviceN color space, as shown in FIG.12. Therefore, even when the power switch of the apparatus is turned onagain, a print process can be done according to the previous settingcontents.

[0091] The operation process of the CPU 1 of the printer of thisembodiment will be described below with reference to the flow chart ofFIG. 13.

[0092] It is checked in steps S24 and S25 if the color space of printdata received from the host computer is the Separation color space orDeviceN color space. If the color space of print data is neither ofthem, i.e., if it is one of DeviceRGB, DeviceCMYK, and DeviceGray, theflow advances to step S26 to execute a print process according to adescription of PS data.

[0093] If it is determined in step S24 that the received print data isdata of the Separation color space, the flow advances to step S27 tomake conversion into a substitute color space according to itsdescription. The flow then advances to step S28 to load data of“Separation color management” in the nonvolatile memory 5 and to checkif its flag is ON or OFF, i.e., if color management is to be applied. Ifcolor management is ON, the flow advances to step S26 to execute theprocess in FIG. 2 to have the substitute color space as a start point.On the other hand, if it is determined in step S28 that color managementis OFF, the flow advances to step S29 to check if the substitute colorspace is a CMYK color space. If it is determined that the substitutecolor space is other than the CMYK color space, the substitute colorspace is converted into the CMYK color space in step S30. In step S31, aprint process is done according to the CMYK color space.

[0094] If it is determined in step S25 that the received print data isdata of the DeviceN color space, the flow advances to step S32 to makeconversion into a substitute color space according to its description.Next, data of “DeviceN color management” in the nonvolatile memory 5 isloaded to check if its flag is ON or OFF, i.e., if color management isto be applied. If color management is ON, the flow advances to step S26to execute the process in FIG. 2 to have the substitute color space as astart point.

[0095] If it is designated that the color management process is OFF, theflow advances to step S34 to check if the substitute color space is aCMYK color space. If it is determined that the substitute color space isother than the CMYK color space, the substitute color space is convertedinto the CMYK color space in step S35. In step S36, a print process isdone according to the CMYK color space.

[0096] As described above, according to this embodiment, when a pagedescription language such as PS Level 3 designates the Separation colorspace or DeviceN color space as a special color space different fromnormal color spaces, a print process can be done while skipping colormanagement according to user's setups. Hence, the print process can besimplified, resulting in a high print process speed.

[0097] <Third Embodiment>

[0098] The above embodiment has exemplified a case wherein the printdata is data of the Separation color space or DeviceN color space. Whendata of DeviceRGB, DeviceCMYK, or DeviceGray is received andUseCIEColor=true, the sequence shown in FIG. 2 is executedunconditionally.

[0099] However, even a versatile color space such as DeviceRGB,DeviceCMYK, DeviceGray, or the like is converted into the standard colorspace XYZ, and the XYZ color space is then converted into a CMYK colorspace using an output profile. Hence, at least two color spaceconversion processes are required. Such function is unnecessary for auser who wants to print mostly monochrome office documents at highspeed. In other words, such function is required for a user whoprincipally prints graphics arts.

[0100] Hence, according to the third embodiment, whether or not colormanagement is applied can be set not only for the Separation color spaceand DeviceN color space but also for print data of DeviceRGB,DeviceCMYK, and DeviceGray.

[0101] In this case, a selection menu is displayed on the control panel4, as shown in, e.g., FIG. 7, to prompt to the user to select one of“Office” and “Graphic Arts” as a use purpose.

[0102] More specifically, two choices, i.e., “Office” suited to a casewherein office documents that do not require high color reproducibilityare normally printed, and “Graphic Arts” that can print graphics artsand the like with high color reproducibility, are prepared, and the userselects one of them.

[0103] When the user selects “Office”, color management is applied tonone of the Separation color space, DeviceN color space, DeviceRGB,DeviceCMYK, and DeviceGray. When the user selects “Graphic Arts”, theuser can select profiles to be used respectively for DeviceRGB,DeviceCMYK, and DeviceGray, as shown in FIG. 2.

[0104] For example, when print data described in the color space RGB isreceived, the user can select a profile to be used from:

[0105] sRGB

[0106] HDTV γ1.5

[0107] HDTV γ1.8

[0108] HDTV γ2.4

[0109] Custom

[0110] None

[0111] sRGB, HDTV γ1.5, HDTV γ1.8, and HDTV γ2.4 are profiles used uponconverting the color space RGB into a standard color space XYZ, and havedifferent conversion levels. Custom is prepared when the user wants tocreate or download his or her favorite profile (upon reception of apredetermined command from a host computer, a subsequent profile isstored and held). None means that no color management is applied.

[0112] In case of CMYK, the user selects a profile from SWOP, EuroScale,JapanColor, Custom, and None. In case of Gray, the user sets a flagindicating whether or not a conversion process into the XYZ color spaceusing a profile is to be inserted (if the flag is OFF, it is equivalentto None).

[0113] In either case, such setting contents are stored and held in thenonvolatile memory 5.

[0114] In the processing sequence according to the third embodiment, ifa profile set for the color space of interest is “None” in step S26 inFIG. 13, the process is done according to the flow shown in FIG. 1;otherwise, conversion to the XYZ color space according to the setprofile and color conversion according to an Output Profile are made,and a print process is then executed.

[0115] As described above, according to the third embodiment, for a userother than specialized fields such as graphics arts and the like, thenumber of color space conversion processes is reduced upon printingindependently of the color space of input print data. Hence, a highprint process speed can be assured.

[0116] The second and third embodiments have exemplified a case whereinthe printer receives PS Level 3 print data (one of the RGB, CMYK, andGray color spaces), and processes the print data according to the setupcontents of user's choice.

[0117] However, a host computer may execute processes until CMYK data tobe finally output are generated. In this case, the setup contents ofuser's choice may be saved in a hard disk or the like of the hostcomputer, and the above processes may be implemented by a printer driveror an add-on program of a PS printer driver. That is, the scope of thepresent invention includes a computer program. Since a program whichruns on a host computer becomes normally ready to run after a computerreadable storage medium such as a CD-ROM or the like is set and theprogram is copied or installed in a system, such computer readablestorage medium is also included in the scope of the present invention.

[0118] This embodiment has exemplified PS Level 3, and the Separationcolor space and DeviceN color space. However, the present invention isnot limited to PS Level 3 since it can be applied to any other printerdescription languages which can set a substitute color space uponprinting data for a special printing apparatus to a normal printer.

[0119] As described above, according to the above embodiments, officeusers are often satisfied with the colors of a substitute color space,and the color management processing time can be saved accordingly. Onthe other hand, since Graphic Arts users require color reproductionfaithful to an original, color management is applied to meet suchrequirement.

[0120] A Device color space as a substitute color space and an originalDevice color space can be separately processed, and user's desiredactions can be supported compared to a conventional system.

[0121] Also, since default setups are used in accordance with machineperformance, the burden of troublesome user's setups can be removed.

[0122] As described above, according to the present invention, printprocesses of print data expressed by the Separation color space orDeviceN color space, which are convenient for both a user who places animportance on a print speed rather than color reproducibility, and auser who wants high-precision color reproducibility can be implemented.

[0123] Also, according to the above embodiments of the presentinvention, office users are often satisfied with the colors of asubstitute color space, and the color management processing time can besaved accordingly. On the other hand, Graphic Arts users cannot often besatisfied with a substitute color space and require color management.Hence, such users can select color management, thus compensating forcolor reproduction.

[0124] Upon selecting color management, a user's preferred process canbe selected. A Device color space as a substitute color space and anoriginal Device color space can be separately processed, and user'sdesired actions can be supported compared to a conventional system.Also, since default setups are used in accordance with machineperformance, the burden of troublesome user's setups can be removed.

[0125] <Other Embodiments>

[0126] Note that the present invention can be applied to an apparatuscomprising a single device or to system constituted by a plurality ofdevices.

[0127] Furthermore, the invention can be implemented by supplying asoftware program, which implements the functions of the foregoingembodiments, directly or indirectly to a system or apparatus, readingthe supplied program code with a computer of the system or apparatus,and then executing the program code. In this case, so long as the systemor apparatus has the functions of the program, the mode ofimplementation need not rely upon a program.

[0128] Accordingly, since the functions of the present invention areimplemented by computer, the program code installed in the computer alsoimplements the present invention. In other words, the claims of thepresent invention also cover a computer program for the purpose ofimplementing the functions of the present invention.

[0129] In this case, so long as the system or apparatus has thefunctions of the program, the program may be executed in any form, suchas an object code, a program executed by an interpreter, or script datasupplied to an operating system.

[0130] Examples of storage media that can be used for supplying theprogram are a floppy disk, a hard disk, an optical disk, amagneto-optical disk, a CD-ROM, a CD-R, a CD-RW, a magnetic tape, anon-volatile type memory card, a ROM, and a DVD (DVD-ROM, DVD-R orDVD-RW).

[0131] As for the method of supplying the program, a client computer canbe connected to a website on the Internet using a browser of the clientcomputer, and the computer program of the present invention or anautomatically-installable compressed file of the program can bedownloaded to a recording medium such as a hard disk. Further, theprogram of the present invention can be supplied by dividing the programcode constituting the program into a plurality of files and downloadingthe files from different websites. In other words, a WWW (World WideWeb) server that downloads, to multiple users, the program files thatimplement the functions of the present invention by computer is alsocovered by the claims of the present invention.

[0132] It is also possible to encrypt and store the program of thepresent invention on a storage medium such as a CD-ROM, distribute thestorage medium to users, allow users who meet certain requirements todownload decryption key information from a website via the Internet, andallow these users to decrypt the encrypted program by using the keyinformation, whereby the program is installed in the user computer.

[0133] Besides the cases where the aforementioned functions according tothe embodiments are implemented by executing the read program bycomputer, an operating system or the like running on the computer mayperform all or a part of the actual processing so that the functions ofthe foregoing embodiments can be implemented by this processing.

[0134] Furthermore, after the program read from the storage medium iswritten to a function expansion board inserted into the computer or to amemory provided in a function expansion unit connected to the computer,a CPU or the like mounted on the function expansion board or functionexpansion unit performs all or a part of the actual processing so thatthe functions of the foregoing embodiments can be implemented by thisprocessing.

[0135] As many apparently widely different embodiments of the presentinvention can be made without departing from the spirit and scopethereof, it is to be understood that the invention is not limited to thespecific embodiments thereof except as defined in the appended claims.

What is claimed is:
 1. A method of controlling an image formingapparatus, which converts print data into a device-independent standardcolor space according to a description of the print data, converts dataof the standard color space into a print color space according to aprofile depending on print unit, and prints the converted data,comprising: a setting step of setting whether or not a conversionprocess into the standard color space is skipped, and storing andholding that setup in predetermined storage unit; and a control step ofdirectly converting, when it is set in the setting step that theconversion process into the standard color space is skipped, the printdata into a color space of the print unit according to the descriptionof the print data.
 2. The method according to claim 1, wherein thedescription of the print data includes an RGB space as luminance colorcomponents, a CMYK space as density color components, and a gray spaceas color spaces to be printed.
 3. The method according to claim 2,wherein the setting step includes a step of making setups for respectivecolor spaces.
 4. The method according to claim 2, further comprising aselection step of selecting one of a graphic art or an office documentas a print purpose, and wherein the setting step includes a step ofsetting, when a print process of an office document is selected in theselection step, to skip the conversion process into a standard colorspace for each color space.
 5. An image forming apparatus which convertsprint data into a device-independent standard color space according to adescription of the print data, converts data of the standard color spaceinto a print color space according to a profile depending on print unit,and prints the converted data, comprising: a setting unit for settingwhether or not a conversion process into the standard color space isskipped, and storing and holding that setup in predetermined storageunit; and a control unit for, when it is set by said setting unit thatthe conversion process into the standard color space is skipped,directly converting the print data into a color space of the print unitaccording to the description of the print data.
 6. A method ofcontrolling an information processing apparatus, which converts printdata into a device-independent standard color space according to adescription of the print data, converts data of the standard color spaceinto a print color space according to a profile depending on print unit,and outputs the converted data to a printing apparatus, comprising: asetting step of setting whether or not a conversion process into thestandard color space is skipped, and storing and holding that setup inpredetermined storage unit; and a control step of directly converting,when it is set in the setting step that the conversion process into thestandard color space is skipped, the print data into a color space ofthe print unit according to the description of the print data.
 7. Aninformation processing apparatus which converts print data into adevice-independent standard color space according to a description ofthe print data, converts data of the standard color space into a printcolor space according to a profile depending on print unit, and outputsthe converted data to a printing apparatus, comprising: a setting unitfor setting whether or not a conversion process into the standard colorspace is skipped, and storing and holding that setup in predeterminedstorage unit; and a control unit for, when it is set by said settingunit that the conversion process into the standard color space isskipped, directly converting the print data into a color space of theprint unit according to the description of the print data.
 8. A computerprogram which serves as an information processing apparatus, whichconverts print data into a device-independent standard color spaceaccording to a description of the print data, converts data of thestandard color space into a print color space according to a profiledepending on print unit, and outputs the converted data to a printingapparatus, said computer program serving as: a setting step of settingwhether or not a conversion process into the standard color space isskipped, and storing and holding that setup in predetermined storageunit; and a control step of directly converting, when it is set in thesetting step that the conversion process into the standard color spaceis skipped, the print data into a color space of the print unitaccording to the description of the print data.
 9. A computer readablestorage medium storing a computer program of claim
 8. 10. A method ofcontrolling an image forming apparatus which receives print dataexpressed by a Separation color space or DeviceN color space, convertsthe print data into a print color space, and prints the converted data,comprising: a setting step of setting whether or not color management isapplied; a conversion step of converting the received print dataexpressed by the Separation color space or DeviceN color space into asubstitute color space according to a description thereof; a firstconversion step of converting, when it is set in the setting step thatcolor management is applied, the color space obtained in the conversionstep into a print color space via a color management process; and asecond conversion step of converting, when it is set in the setting stepthat color management is not applied, the color space obtained in theconversion step into a print color space without any color managementprocess.
 11. The method according to claim 10, wherein the secondconversion step includes a step of executing, when the substitute colorspace is a color space equivalent to print color components, a printprocess using the substitute color space.
 12. The method according toclaim 10, wherein the print data is data described using PostScript,when color management is applied, a color conversion process when aUseCIEColor parameter is True is executed, and when color management isnot applied, a color conversion process when a UseCIEColor parameter isfalse is executed.
 13. An image forming apparatus which receives printdata expressed by a Separation color space or DeviceN color space,converts the print data into a print color space, and prints theconverted data, comprising: a setting unit for setting whether or notcolor management is applied; a conversion unit for converting thereceived print data expressed by the Separation color space or DeviceNcolor space into a substitute color space according to a descriptionthereof; a first conversion unit for, when it is set by said settingunit that color management is applied, converting the color spaceobtained by said conversion unit into a print color space via a colormanagement process; and a second conversion unit for, when it is set bysaid setting unit that color management is not applied, converting thecolor space obtained by said conversion unit into a print color spacewithout any color management process.
 14. A method of controlling aninformation processing apparatus which receives print data expressed bya Separation color space or DeviceN color space, converts the print datainto a print color space, and outputs the converted data to a printingapparatus, comprising: a setting step of setting whether or not colormanagement is applied; a conversion step of converting the receivedprint data expressed by the Separation color space or DeviceN colorspace into a substitute color space according to a description thereof;a first conversion step of converting, when it is set in the settingstep that color management is applied, the color space obtained in theconversion step into a print color space via a color management process;and a second conversion step of converting, when it is set in thesetting step that color management is not applied, the color spaceobtained in the conversion step into a print color space without anycolor management process.
 15. An information processing apparatus whichreceives print data expressed by a Separation color space or DeviceNcolor space, converts the print data into a print color space, andoutputs the converted data to a printing apparatus, comprising: asetting unit for setting whether or not color management is applied; aconversion unit for converting the received print data expressed by theSeparation color space or DeviceN color space into a substitute colorspace according to a description thereof; a first conversion unit for,when it is set by said setting unit that color management is applied,converting the color space obtained by said conversion unit into a printcolor space via a color management process; and a second conversion unitfor, when it is set by said setting unit that color management is notapplied, converting the color space obtained by said conversion unitinto a print color space without any color management process.
 16. Acomputer program for an information processing apparatus which receivesprint data expressed by a Separation color space or DeviceN color space,converts the print data into a print color space, and outputs theconverted data to a printing apparatus, said computer program servingas: a setting unit for setting whether or not color management isapplied; a conversion unit for converting the received print dataexpressed by the Separation color space or DeviceN color space into asubstitute color space according to a description thereof; a firstconversion unit for, when it is set by said setting unit that colormanagement is applied, converting the color space obtained by saidconversion unit into a print color space via a color management process;and a second conversion unit for, when it is set by said setting unitthat color management is not applied, converting the color spaceobtained by said conversion unit into a print color space without anycolor management process.
 17. A computer readable storage medium storinga computer program of claim 16.